Ancelotti recently made his return to football management at Paris St Germain and called for Blues boss Andre Villas-Boas to sell Drogba after revealing that he has been offered the chance to sign Torres during this month's transfer window.
Drogba is still to sign the 12-month contract extension offered to him by Chelsea and Ancelotti believes the time is right for his old club to sell the Ivorian to allow Torres the chance to establish himself as first-choice striker at Stamford Bridge.
The Italian told Gazzetta dello Sport: "I don't judge the work of a colleague. What I would say is training Chelsea, when the club is in the middle of a major generational change, is complicated.
"Take Torres and the crisis he has lived through there. I now know if you decide to invest strongly in him, you have to sell Drogba.
"Didier is like Filippo Inzaghi was at AC Milan. He simply devours any competition," added Ancelotti.
"It's not that he's evil - nor was Inzaghi - it's just the way they are."